Changes the streamable state of the player to the value of the second argument. The third argument is whether or not the player should disappear immediately.
The second and third arguments are integers but they are treated as booleans. That means 0 is false and every other value is true.
Sets if a player should be streamable/visible for other players. The third parameter specifies whether he should disappear immediately or when the streams are updated (maximum delay is `stream_rate` in gmp_server.ini).
